NAME
Ubic::Daemon - daemon management utilities
VERSION
version 1.36_02
SYNOPSIS
use Ubic::Daemon qw(start_daemon stop_daemon check_daemon);
start_daemon({bin => '/bin/sleep', pidfile => "/var/lib/something/pid"});
stop_daemon("/var/lib/something/pid");
$daemon_status = check_daemon("/var/lib/something/pid");
DESCRIPTION
This module provides functions which let you daemonize any binary or perl coderef.
Main source of knowledge if daemon is still running is pidfile, which is locked all the time after daemon was created.
Note that pidfile format is unreliable and can change in future releases (it's actually even not a file, it's a dir with several files inside it), so if you need to get daemon's pid, don't try to read pidfile directly, use check_daemon()
function.
- stop_daemon($pidfile)
- stop_daemon($pidfile, $options)
-
Stop daemon which was started with
$pidfile
.It sends SIGTERM to process with pid specified in
$pidfile
until it will stop to exist (according tocheck_daemon()
method).If it fails to stop process after several seconds, exception will be raised (this should never happen, assuming you have enough grants).
Options:
- timeout
-
Number of seconds to wait before raising exception that daemon can't be stopped.
Return value:
not running
if daemon is already not running;stopped
if daemon is stopped by SIGTERM. - start_daemon($params)
-
Start daemon.
Throws exception if anything fails.
Successful completion doesn't mean much, though, since daemon can fail any moment later, and we have no idea when its initialization stage finishes.
Parameters:
- bin
-
Binary which will be daemonized.
Can be string or arrayref with arguments. Arrayref-style values are recommended in complex cases, because otherwise
exec()
can invoke sh shell which will immediately exit on sigterm. - function
-
Function which will be daemonized. One and only one of function and bin must be specified.
Function daemonization is a dangerous feature and will probably be deprecated and removed in future.
- name
-
Name of guardian process. Guardian will be named "ubic-guardian $name".
If not specified, bin's value will be used, or
anonymous
when daemonizing perl code. - pidfile
-
Pidfile is a dir in local filesystem which will be used as a storage of daemon's info.
It will be created if necessary, assuming that its parent dir exists.
- stdout
-
Write all daemon's output to given file. If not specified, all output will be redirected to
/dev/null
. - stderr
-
Write all daemon's error output to given file. If not specified, all stderr will be redirected to
/dev/null
. - ubic_log
-
Optional filename of ubic log. Log will contain some technical information about running daemon.
If not specified, this logging facility will be disabled.
- cwd
-
Change working directory before starting a daemon. Optional.
- env
-
Modify environment before starting a daemon. Optional. Must be a plain hashref if specified.
- term_timeout
-
Can contain integer number of seconds to wait between sending SIGTERM and SIGKILL to daemon.
Zero value means that guardian will send sigkill to daemon immediately.
Default is 10 seconds.
- check_daemon($pidfile)
-
Check whether daemon is running.
Returns instance of Ubic::Daemon::Status class if daemon is alive, and false otherwise.
BUGS AND CAVEATS
Probably. But it definitely is ready for production usage.
This module is not compatible with Windows by now. It can be fixed by implementing correct Ubic::Daemon::OS::Windows
module.
If you wonder why there are ubic-guardian
processes in your ps
output, see Ubic::Manual::FAQ, answer is there.
SEE ALSO
Ubic::Service::SimpleDaemon - simplest ubic service which uses Ubic::Daemon
There are also a plenty of other daemonizers on CPAN:
MooseX::Daemonize, Proc::Daemon, Daemon::Generic, Net::Server::Daemonize.
AUTHOR
Vyacheslav Matyukhin <mmcleric@yandex-team.ru>
COPYRIGHT AND LICENSE
This software is copyright (c) 2012 by Yandex LLC.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.